Soil is the loose material that covers the land surface of the earth, supports the growth of plants and acts as a habitat for numerous organisms.
It is a loose combination of physical (organic and inorganic) and biotic materials.
The development of soil (called as Paedogenesis) takes thousands of years. So, it can be called as a non-renewable resource. Despite being a non-renewable natural resource, soil is under heavy stress due to bad practices of agriculture; overuse of inputs like water, fertilizers and pesticides; deforestation; overgrazing; over development and pollution.
Soil Erosion and its Control
The depletion of top-productive soil by the agency of water or wind is called as soil erosion.
Some farming methods also encourage soil erosion through these agencies. Those farming methods are –Mono agriculture or Mono cropping, wrong methods of ploughing or tilling the land, overgrazing by cattle like goats and sheep, deforestation etc.
There are many different methods of controlling soil erosion. Those methods are –
(i) Rotation of crops or Alternate Cropping,
(ii)Construction of proper drainage or outlets to carry away the water of fields without causing soil erosion,
(iii) Plantation – like Afforestation, reforestation, Compensatory Plantation etc.
(iv)Control on overgrazing,
(v) Terracing on hill slopes to check direct flow of water,
(vi )Adoption of proper methods of cultivation,
(vii) Putting ban on the farming on land near river banks.
Conservation of Soil
Making the best use of soil, together with protecting it from all types of factors that may cause its degradation is called as soil conservation.
Soil is a vital life support system. No life is possible without soil as plants, our food- providers, can not grow without it. It provides shelter to numerous types of micro organisms and animals.
The conservation of soil is needed urgently because degradation of soil across the world has become a matter of particular concern today.
According to a report of the United Nations Environmental Programme (UNEP), it is estimated that about 13 percent of land in Asia and Pacific has been degraded due to clearance of forests and introduction of invasive species.
The clearance of forests is causing a decline in the soil structure and fertility.
Himalayas, Central Asia, China, South Pacific and Australia are experiencing losses of top soil due to heavy erosion by water. Afghanistan, India, Iran and Pakistan are loosing considerable amount of top soil through erosion by wind also.
The agricultural mismanagement is causing chemical soil degradation which is seen in the form of acidification and salinization of soil. Out of about 1977 m ha dry land in Asia, more than one half are affected by desertification. All these cases of land degradation are related directly or indirectly to the land use practices like agricultural expansion and intensive agriculture.
Practices of Conservation and Management of Soil
The judicious use of soil, maintenance of its fertility and prevention of its loss by all possible means, is called as Conservation and Management of Soil. The Conservation and Management of Soil involves a number of practices .These practices are –
. Proper tillage of land and Land use Management,
. Judicious use of inputs like water, fertilizers, and pesticides,
. Use of manure like compost and green manure,
. Use of bio- fertilizers on the place of synthetic chemical fertilizers,
. Use of bio- pesticides on the place of synthetic chemical fertilizers, &
.Prevention and control of soil erosion through various different methods– like, plantation conservation of grasslands and forests and, through Social Forestry and Agroforestry.
